Question

How fo u solve 7xsqaured=-21

Answer 1

Step-by-step explanation:

`7x^2=-21`

First we have to divide both sides by 7:

`\begin{gathered} (7x^2)/(7)=(-21)/(7) \\ x^2=-3 \end{gathered}`

And now we have to take square root on both sides:

`\begin{gathered} \sqrt[]{x^2}=\pm\sqrt[]{-3} \\ x=\pm\sqrt[]{-3} \end{gathered}`

Since the number inside the square root is negative we can rewrite it as:

`x=\pm\sqrt[]{i^23}=\pm i\sqrt[]{3}`

This is a quadratic equation, so it has two solutions.

Answer:

The solutions are:

• i√3

,

• -i√3